[exim] forward messages as attachments?

Hello,

Is there someway that we can make messages going to aol, be sent as an
attachment to a pre-written message?

Some teachers forward all their mail to aol.com addresses, and when they
open them, they mark messages as spam that have come from our provider
which we smarthost through.

This then makes aol think our provider is a spammer; and they call us up
and yell at us.

So is there someway that we can 'wrap' our messages that are being
forwarded in some type of email that says.. "This came from us, don't
mark it as spam, click on the attachment to open the message.. "

I know spam assassin had something that it did, when a message was spam..